Number of sub arrays with odd sum | C # code to find count of sub - arrays with odd sum ; A temporary array of size 2. temp [ 0 ] is going to store count of even subarrays and temp [ 1 ] count of odd . temp [ 0 ] is initialized as 1 because there a single odd element is also counted as a subarray ; Initialize count . sum is sum of elements under modulo 2 and ending with arr [ i ] . ; i ' th ▁ iteration ▁ computes ▁ sum ▁ ▁ of ▁ arr [ 0 . . i ] ▁ under ▁ modulo ▁ 2 ▁ ▁ and ▁ increments ▁ even / odd ▁ count ▁ ▁ according ▁ to ▁ sum ' s value ; 2 is added to handle negative numbers ; Increment even / odd count ; An odd can be formed by an even - odd pair ; Driver code
using System ; class GFG { static int countOddSum ( int [ ] ar , int n ) { int [ ] temp = { 1 , 0 } ; int result = 0 , val = 0 ; for ( int i = 0 ; i <= n - 1 ; i ++ ) { val = ( ( val + ar [ i ] ) % 2 + 2 ) % 2 ; temp [ val ] ++ ; } result = temp [ 0 ] * temp [ 1 ] ; return ( result ) ; } public static void Main ( ) { int [ ] ar = { 5 , 4 , 4 , 5 , 1 , 3 } ; int n = ar . Length ; Console . Write ( " The ▁ Number ▁ of ▁ Subarrays " + " ▁ with ▁ odd ▁ sum ▁ is ▁ " + countOddSum ( ar , n ) ) ; } }